I know it's been a while but I thought I would update you all with the solution.
I installed a toroid ring on the output lines on the VFD. This fixed the issue of the noise affecting the temp probe.
Thanks for all your input!
Briane22 - I don’t think I can change the sampling rate. I will have to read about antialiasing filters.
Itsmoked - I will not ground the brine. I will add that there aren’t any fish in the white tank. And I will try out the probe life ring after I’ve tried the probe in a glass of freshwater...
Redsanke - There is an additional pump that pulls water from the sump and sends it through a plate heat exchanger, degassing tower and protein skimmer. However, this hasn't been running.
The Hex drum filter has a small motor that is used to turn the drum as needed.
Thanks again everyone for the feedback and information. As soon as I'm able, I will be testing out and checking as many things you've all listed. I will certainly update as I go.
In the two tanks next to the white tank we will be adding fish.
I’ll make sure to remove the stainless metal rods that I grounded from the white tank. That didn’t help.
It would be great to discuss this is more detail over the phone but I don’t see anyway to privately contact anyone.
I will...
Itsmoked - What could cause the water to be live?
It’s certainly something I could rule out. When the sump was full and the motor was running I had my hand in the tank multiple times. I’d be very surprised if the water was live. Still something to check
Redsnake - the water is pumped from the white tank you see in the photo into two tanks next to it. The water then flows out of these tanks into the drum filter that is sat on a fiberglass stand in the white tank. The drum filter has a small motor that turns the drum when needed.
Do you think...
Redsnake - yes, the probe is near the drum filter. I’m not quite sure what you mean with the second part of your question.
Electricpete - not sure what you mean by coupling type. You need to dumb things down for me.
The tank itself isn’t grounded. I did bundle some stainless pipe together and...
The pipe passage you can see below the temp probe is for another pump, not pictured. That pump is not on a VFD and has not been running at all
The black thing, is a drum filter. https://hexfilter.com/
Electricpete - No submersible pump. This is the location of the pump that is connected to the VFD. I will try a grounded can or something around the probe to see if that helps.
I did drop in some stainless steel rods into the sump and grounded those, however, that didn't help. I wonder if...
RedSnake - I'd be willing to try another shielded digital temp probe that I can connect with a RJ11 connector. I wouldn't know where to look to find one. You can certainly hook up other probes not made by avtech to this system. Most of the probes I connect to the avtech unit are not made by...
Electricpete - The VFD was only turned off after the temp reading returned to normal
3DDave - It's a RJ11 connection. The wire used is alpha wire, type 78104
Edison123 - I actually bought a new probe as I thought this might be the issue, however, the new probe acts in the same way.
Redsnake - I had to drain the tank to do some work on the system. As soon as I get the tank refilled and the system running. I will test out the probe in a glass jar of...
As a comparison, this is the graph produced by the same type of probe, submerged in the same way, in another system. The only difference is, there isn't a VFD in the room with the probe.
@3DDave - I'm in the process of setting up a plate heat exchanger that using a different temp probe to maintain the correct temp in the system. Currently it's not up and running. The sample rate is every 2 seconds.
@Electricpete - the probe is made by avtech, they don't have the exact ones...
